软件测试实例（好像是具体的测试）

# # Simple tests: # 9 7 8 9 9 9 8 7 9 9 8 9 # # Negative number tests: # -7 -7 -8 -9 -7 -8 -7 -8 -7 -9 -7 -8 # # Mixture: # 7 -9 -7 -8 7 6 4 9 -1 0 9 -7 4 # # Boundary conditions: # 1 1 0 0 2147483647 2147483647 -2147483648 -2147483648